Rock-drill.



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ROCK DRILL.

APPLIQAHON FILED ocT.2, |912,

Patented May H, 15%.

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APPLICATION ILED OCT. 2. NH2. Eatened May '31, 19H5.

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:bil improvements in .Rock-Drills,

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Specification of 'Letters latent.

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T all whom it may concern: y

Be it known that l, ,WILLiAM L. Sm'rrn'a citizen ot the United States, residing'at Chicago. in the county of Cook and State of illinois. l ave invented certain new and useot which the 'follwing is a specification.

My invention relates to rock drills and similar devices having reciprocatory ele ments, and more particularly' to hammer drills of the type shown and described in my application for Patent No. 588,95l, filedv in the United States Patent @dice October 25, 1910. A drill of the type above referred to comprises, essentially, a rotary crank wheel and a reciprocating hammer which is operatively connected therewith through the instrumentality ot a cylinder which is secured to the Wrist of the wheel and a piston which has a reciprocating movement in the cylinder and whose rod is rigidly conn the hammer. The latter is guided in a circular surface with which it is in linear Contact and it inipinges during its forward stroke upon the cutting tool which is longitudinally movably supported in axial alinenjient with said surface.

The principal objects of the present in yention reside 1st, in the provision of a Wrist connection between the crank Wheel and tl e cylinder which permits e self-adjustment oi." the latter about an axis trans verse to that about which it rotates during its circuler motion 'with the Wheel, thereby assuring the' proper operation et the machine even though the operatingfperts thereof are by wea r or imperfect connections, placed out ot alinenient- 2nd, in mounting the element which provides the cylindrical guiding surface seth-at it may rotate about its longitudin'al axis whereby to equalize the wear of said surface bythe sliding and gravitative action olthe reciprocating hammer. 3rd, in formingr the element which provides the guiding surface integral which the cutting tool mov-ably supported, so that the two par-ts may rotate in unison. flth, in providing e mechanism whereby the said element may be rotated either by hand or by the rotarymotion oi the crank Wheel; 5th, in essociating with the said mechanism, ineens for feeding the drill housing to advance the cutting tool into the bore produced thereby, and 6th, in proiidiug an oiling system by which a' lubricant is continuously supplied with the chuck in is longitudinally to the frictiona-lly engaging parts of the crank iyheel, cylinder and piston.

An electric motor is mounted in the drill housing and. is by a suitable transmissionv mechanism, connected with the crank Wheel, thus rendering the machine entirely selif'.- contained, and the drill housing .is longitu dinally slidably mounted upon a guide shell of the usual construct-ion which is provided with means for securing it upon a column or other suitable support.

An embodiment of my invention has been illustrated in the accompanying drawings in the various views of which like parts are similarly designated and in which,

Figure 1 represents a vertical section through. my improved drill, Fig. 2, e horizontal section through the same taken along the line 52-2, Fig. l, Fig. 3, a transverse section along the line 3-3 Fig. l, and Fig. Il, a similar section taken along the line Jl-4i, Fig. l..

Referring more specilically to the drawings the reference character 2 designates the guide shell upon which the housing 6 of the machine is longitudinally movably mounted and ivhichis provided with the usual standard 3 for its connection with a column or other suitable support. The shell hes .in 'its sides, parallel il-shaped guide grooves in which correspondingly shaped ilangos l on the lower portion of the drill housing are slidably fitted, and a nut 5 secured in the shell intermediate of its extremities is provided for its connection with the guide screw i'v Whose operative association With the drillI housing de vribed. A vertical, headed Ystud-shaft" 8 which at one of its ends isrigidly secured in a threaded opening in the upper portion ot the housing, provides an axle l'or the support of a crank wheel 3, the rotary movement of which is rendered equable by the provision or a counteiipoise opposite to the point at which the cushion cylinder 52 is connected with the same. bearings 10 applied between the shaft and the crank Wheel are provided to reduce friction during the latters rotary motion and an axial bore l2 in the shaft S connects lwith a chamber i3 Within the crank Wheel for the supply of a lubricant thereto from a source connected' with the said bore at the outer end-olE the shaft. A wrist 14C which is rotatably mounted in ball bearings 1'5 on the vcrank wheel has exteriorly of the said wheel,

will hereinafter be A. pair' of ball same purpose a nu'mber of openings 34 whichl a `:forked bearing lli for the cushion cylinder 52. The latter is torthis end provided with. trufmiions 17 whichl are rotatably fitted in bearings at the ends of the two members of the wrist-forli between which the cylinder is loosely disposed. An, axially bored nipple 18 extending laterally from the cylinder, projects loosely into an axial recess in vthe body portion ci the wrist ld which is furithermore provided with a transverse passage 19 for the connection of said recess with a space around the wrist which commuuicates with the oil chamber of the crank Wheel. The lubricant contained in. the lat ter is thus continuously supplied to the in terior of the cylinder as well as to the bearings of the wheel and the wrist.

The electric motor 2O which supplies the driving power for the machine is installed in a 'compartment at the rear end. of the housing and a gear wheel 2l mounted on its armature shaft is throughthe instrumen* tality of an intermediate' gear 22, operav tively connected with a gear wheel 23 on the crank wheel 9. A piston 24 which has a reciprocating movement in the cylinder 52 is formed integral with a rod 25 which is slidingly supported in an elongated bearing; 26 formed on the cylinder-head. which closes the forward end of the same, and a spherical impact hammer 27 detachably connectedv 'the outer extremity ci the rod is slide/bly tted in a hollow guide cylinder 2S which is rotatably mounted in a cylindrical sleeve 29 at the forward end of the housing, upon bearings 30.

ln the construction shown in the drawings the cylinder 28 is formed integral with a chuck 3l which protruding through an opening in the forward end of the housing has an axial bore in which the cutting tool 32 is longitudinally movahiy fitted. To avoid compression of the air in the guiding* space of the cylinder 28 during forwardV movement of the hammeri the latter is provided with a plurality of longitudinal passages 33 andthe said cylinder has forthe connect its interior' at the forward end thereof with Athe surrounding atmosphere. It will be understood that if so desired either one of th'eries of nated.

The feed screw 7 hereinbeore referred to extends at its forward end into an opening in the housing which being closed at one of' its ends, provides a thrust bearing 35 through which a longitudinal movement of the' screw is transmitted to the housingl S. 'At itsopposite, rearmost end the screw I is ysupported in bearings on the housing between which a thrust bearing 3'? a coiled springBS are applied to render the Contact between the end of the cutting tool and the breast of passages may be elimithe hole produced thereby,

arcaica resilient. A crank S9 is vattached at the rear end of the feed screw for its rotation by hand and the rotary movement of the screw is' transmitted to the cylinder 28 by means cfa pinion 39 on the forward end of the screw and a therewith meshing gearwheel ll0 secured around the cylinder. By rotation of the screw through the medium ci' the crank, the cylinder and the chuck may 'thus be rotated at the same time that the hour@ ing is moved forwardly to advance the cutting tool Ainto the hole produced thereby or the same results may be obtained automati` cally by the. rotary motion ci' the crank wheel through the instrumentality of a g@ mechanism,4 the construction of which will new be explained. A lever 4l which has an oscillating movement about a vertical axis in'bearings in the housing 6, carries at one oli its ends an antiffriction roller Ll2 which g5, engages the peripheral surface of a cam i3 which is keyed to the crank wheel 9. A setl of pawls d4 mounted at the opposite end of the lever isby means of a spring e5, held in yieldineengagement withA a ratchet wheel @e 4t lined' on the rotary linder 28 and another set oi pawls 47 which likewise engage/ the teeth of the ratchet wheel, is provided to' preventretrograde motion of the same. A. bar i8 eztending transversely oi' the housg5 ing engages the upper surface o the lever el at the forward end of the same to guide it during its' oscillatory movement in a hori` zontal plane and to thus prevent binding of its shaft inlthe bearings on t e housing and 30g a spring 555 is applied between a lug on the housing and the lever 4l to return the latter to its normal f position aer it has been moved about its ulcrum by the, action of the cam t3 on the roller 42.

When it is desired to rotate the cylinder and feed the housing automatically7 the pawls 4A on the lever are placed in engagement with the teeth .on the ratchet wheel, while the other partsremain in the position 11u they occupied for operating the cylinder by hand. Duringeach revolution of the crank 2, the lever 4:1 oscillatesabout its axis and through the medium of the pawl and ratchet movement, imparts a partial rotation to the 115 cylinder 28. The rotary movement of the latteris, by means 'of the gear wheel 40 and the pinion 39, transmitted to the feed screw which in consequence imparts a longitudinal movement to the housing 6. ln case 12e it is desired to only rotate the cylinder automatically and' feed the drill housing by hand, the pinion on the feed screw is moved out of engagement with the gear wheel onth'e cylinder,which is readily accom- 125 plished by withdrawing the pin 49 whichl normally? prevents its displacement on the screw and sliding the pinion along the :feather 50 to a position at the opposite side of the said pin. d thrust boo-ring el.

. a cylinder having a adsense plied between the cylinder 2B and the end motion of the cra-nk wheel and the compression of air in the said cylinder during a portion of its circular movement, provides a pneumatic spring which, during another portion of the said movement, drives the 'piston forward thereby causing the hammer 27 to forcibly engage the end of the cutting tool 22 Whose shank projects into the interior of the guiding cylinder, and the compression of air alternately at opposite sides of the piston provides cushions which by absorption of the reactive forces relieve the parts of the machine of detrimental shocks.

While the preferred embodiment of my invention is in connection with its use for rock drills, it may be used for various other purposes in which a reciprocatory element is employed, and in the claims I do not intend to limit the scope oi' the invention to rock drills. Having thus described my invention what I claim and desire to secure by Letters-Patent is f y 1. In an impact machine, a rotary crank, a cylinder having a wrist connection therewith, a piston in said cylinder, a hammer connected with said piston, and a tool disposed to be engaged by said hammer, said crank having a chamber in communication with the interior of said cylinder, for the supplyv of a lubricant thereto.

2. In an impact machine, a shaft having a passage for the supply of a lubricant, a crank on said shaft, having a chamber in communication with said passage, a wrist rotatable on' said shaft and having a recess Tin communication with said chamber, a cylfinder on said wrist, lcommunication with said' recess, a piston in its interior being 1n said cylinder, a hammer connected with said iston, and a tool disposed to be engaged by the said hammer.`

3. In an impact machine, a rotary crank,

wrist connection therewith, a piston in said cylinder, a hammer 'gitudinal axis connected with said piston, and a tool disposed to be engaged by said hammer, said crank, wrist-connection and cylinder having cooperative means for the supply of allnbricant to the interior of the cylinder during movement of the said crank. el. In an impact machine, a rotary crank, a wrist rotatably mounted thereon and having a forked bearing, a trunnioned cylinder mounted in said bearing so as to be capable of movement forvarying the angle between its longitudinal axis and the axis of rotation of the wrist, a piston in said cylinder, an impact-element connected with said piston, and means for guiding said element for rectilinear reciprocation.

5. In an impact machine, a support having a nut, a housing having bearings, a feed screw extending through said nut and rotatably mounted in said bearings, a bearing to resist end-thrust of said screw and a spring applied between said thrust bearing and one.. of the first mentioned bearings. 75

6.' In 'an impact machine, a support, a

housing movable thereon, an impact element,

a rotary tool-holding chuck in said housing, capable of guidingsaid impact element for movement to engage a tool held in the chuck, means for converting a rotaryrnovement of the chuck into a rectilinear movement of the housing on the support, for feeding the same toward the work engaged by the tool, and operating mechanism insaid housing in operative connection with the impact ele` ment and the said rotary chuck. f 7. In an impact-machine, a rotary crank, a wrist rotatably mounted thereon, a cylinder .having a universal connection with said wrist, whereby it is capable o move ment for varying the angle between its lon and the axis of rotation of the wrist, a piston in said cylinder, an imactelement connected with said piston,

wrrri'an i.. snirn.

Witnesses HARRY J. CHENEY, OsMUND ERICKSON.

-and means for guiding said element for ree- 

